Ooh that makes sense now, I was adding the normal force into the mix before. It was just making it complicated. So you don't need the normal force?

No. It just tells us that and . It wouldn't tell us much, because the masses aren't known. Since their is tension in the string and they are inclined at different angles, it would have been best to look at the forces along the incline, rather than perpendicular to the incline.